Dmitry Monakhov <dmonakhov@xxxxxxxxxx> writes:
> tytso@xxxxxxx writes:
>
>> On Tue, May 25, 2010 at 06:28:29PM +0400, Dmitry Monakhov wrote:
>>> tytso@xxxxxxx writes:
>>>
>>> > On Thu, Apr 22, 2010 at 08:31:11AM +0400, Dmitry Monakhov wrote:
>>> >> @@ -2480,6 +2480,11 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
>>> >> out:
>>> >> ext4_ext_drop_refs(path);
>>> >> kfree(path);
>>> >> + if (err == EAGAIN) {
>>> >
>>> > Surely this should be "err == -EAGAIN", no? I'm curious how this
>>> > patch worked for with this typo....
>>> As usually it fix one thing, and broke another :(.
>>> So in case of alloc/truncate restart truncate will be aborted,
>>> so i_size != i_disk_size which must be caught by fsck (my test run
>>> it every time) but this never happens which is very strange.
> Ohh i ment to say blocks beyond i_disk_size due to aborted truncate.
>> What test case are you using? And does it require a system crash to
>> show up, or are you seeing an fsck problem after the test completes
>> and you unmount the file system?
> crash is not required.
> I use proposed xfsqa tests from the bug, may be i've changed some
> numbers, but core idea stays the same.
> mount /dev/sdb1 /mnt
> fsstress ..... &
> sleep 300; killall -9 fsstress
> umount /mnt
> fsck -f /dev/sdb1
> After you have spotted the mistypo i've add explicit fault injection
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -98,9 +98,15 @@ static int ext4_ext_truncate_extend_restart(handle_t
>>> > *handle, int needed)
> {
> int err;
> + static int fault = 0;
>
> if (!ext4_handle_valid(handle))
> return 0;
> + if (inode->i_size % 1234 == 0 && fault++ % 2) {
> + printk("EXT4 TRUNC fault inject inode:%ld\n",inode->i_ino);
> + dump_stack();
> + return -EAGAIN;
> + }
>
> And i've got complain from fsck about incorrect i_size which should be
> increased due to block beyond i_disk_size as expected.
> And when i've fixed the mistypo i've had different complain due to
> bitmap difference.
This is more than just a bad luck, seems what my brain wasn't enabled
yesterday and at the time i wrote the patch.
I've added 'again' label but forgot to reinitialize "i" variable to zero
again :( . Sorry for wasting you time for this sort of foolishness.
Now it is pass all my tests:
1) fsstress -p100
2) fsstress -p100 with fault injection from journal_restart.
See correct version attached.
>From da147cf458b2b68486b063725afa2d2a2f8d6e2e Mon Sep 17 00:00:00 2001
From: Dmitry Monakhov <dmonakhov@xxxxxxxxxx>
Date: Wed, 26 May 2010 15:37:03 +0400
Subject: [PATCH] ext4: restart ext4_ext_remove_space() after transaction restart v2
If i_data_sem was internally dropped due to transaction restart, it is
necessary to restart path look-up because extents tree was possibly
modified by ext4_get_block().
https://bugzilla.kernel.org/show_bug.cgi?id=15827
Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx>
---
fs/ext4/ext4.h | 1 +
fs/ext4/extents.c | 21 +++++++++++++++------
2 files changed, 16 insertions(+), 6 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 3b63837..36e6a32 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1162,6 +1162,7 @@ enum {
EXT4_STATE_DA_ALLOC_CLOSE, /* Alloc DA blks on close */
EXT4_STATE_EXT_MIGRATE, /* Inode is migrating */
EXT4_STATE_DIO_UNWRITTEN, /* need convert on dio done*/
+ EXT4_STATE_EXT_TRUNC, /* truncate is in progress, modified under i_data_sem */
};
#define EXT4_INODE_BIT_FNS(name, field) \
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index c7c304f..3321f57 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -107,11 +107,8 @@ static int ext4_ext_truncate_extend_restart(handle_t *handle,
if (err <= 0)
return err;
err = ext4_truncate_restart_trans(handle, inode, needed);
- /*
- * We have dropped i_data_sem so someone might have cached again
- * an extent we are going to truncate.
- */
- ext4_ext_invalidate_cache(inode);
+ if (!err && !ext4_test_inode_state(inode, EXT4_STATE_EXT_TRUNC))
+ err = -EAGAIN;
return err;
}
@@ -2359,7 +2356,7 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
int depth = ext_depth(inode);
struct ext4_ext_path *path;
handle_t *handle;
- int i = 0, err = 0;
+ int i, err = 0;
ext_debug("truncate since %u\n", start);
@@ -2368,12 +2365,16 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
if (IS_ERR(handle))
return PTR_ERR(handle);
+again:
ext4_ext_invalidate_cache(inode);
/*
* We start scanning from right side, freeing all the blocks
* after i_size and walking into the tree depth-wise.
*/
+ i = 0;
+ ext4_set_inode_state(inode, EXT4_STATE_EXT_TRUNC);
+ depth = ext_depth(inode);
path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_NOFS);
if (path == NULL) {
ext4_journal_stop(handle);
@@ -2478,6 +2479,11 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
out:
ext4_ext_drop_refs(path);
kfree(path);
+ if (err == -EAGAIN) {
+ err = 0;
+ goto again;
+ }
+ ext4_clear_inode_state(inode, EXT4_STATE_EXT_TRUNC);
ext4_journal_stop(handle);
return err;
@@ -3327,6 +3333,9 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
ext_debug("blocks %u/%u requested for inode %lu\n",
map->m_lblk, map->m_len, inode->i_ino);
+ if (unlikely((flags & EXT4_GET_BLOCKS_CREATE)) &&
+ ext4_test_inode_state(inode, EXT4_STATE_EXT_TRUNC))
+ ext4_clear_inode_state(inode, EXT4_STATE_EXT_TRUNC);
/* check in cache */
cache_type = ext4_ext_in_cache(inode, map->m_lblk, &newex);
if (cache_type) {
--
1.6.6.1
